Cast Steel Trunnion Ball Valve - Tawajod Industrial

The cast steel trunnion mounted ball valve has been designed two piece body type or three piece body type and with two floating seats, which are movable under the pressure of medium.

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The cast steel trunnion mounted ball valve has been designed two piece body type or three piece body type and with two floating seats, which are movable under the pressure of medium. Under the bottom of seats, seat pre-loading springs are positioned to ensure two floating seats can attach the ball’s surface tightly, other more, pressure of medium also can push seats to attach ball tightly to ensure sealing more reliable.

The cast steel trunnion ball valve is equipped with a movable seat seal ring which can generate displacement under the pressure of medium. In case that any medium pressure exists, the pressure will press the valve seat seal ring onto the ball tightly, guaranteeing the sealing performance of the ball valve.

Upon request, sealant lubrication fittings are installed. In the event of seat insert or stem seal damage, external or internal leakage can occur. Emergency sealant injection can save the integrity of the valve by incorporating a sealant seal around the stem or between the seat and the ball until such time the valve may be properly serviced.

The spring provided at the stem allow the static charges to be led to the piping. In this way, an electrostatic charging of the ball is eliminated.

The stem is independent of the ball and is a blow-out proof design. As an integral part, a stem has a flange at its lower side. Owing to such a specific design, the stem flange prevents the stem from blowing out. This feature also allows replacement of the ball by generously proportioned mating joint, hence the stem is not affected by the side thrust.

Working Principle of Flanged Ball Valve:

 The ball of the trunnion ball valve is trunnion and supported by two fixed axes connected with the ball. When closed, under the action of medium pressure, the sphere will not produce displacement. Usually, the upper and lower axles connected with the sphere are equipped with rolling bearings or sliding bearings. In order to reduce the friction force of the journal when opening and closing. Reduce operating torque. This trunnion ball valve is suitable for Large dimension Ball valves. The ball of the metal seat trunnion ball valve is fixed by two upper and lower stem. When working, the fluid pressure will not cause the ball to move towards the valve seat, and the valve seat will not be deformed by excessive pressure. The valve stem part is provided with self-lubricating bearing, which reduces friction and has small switch torque. Both seats are pre-tightened by spring. The seal is inlaid with PTFE in the steel fixture, and the rear part of the steel ring is provided with a spring to ensure that the valve seat is close to the sphere. When the abnormal increase of pressure in the valve chamber exceeds the spring tightening force, the valve seat retreats away from the sphere to achieve the effect of automatic pressure relief, and the valve seat is automatically reset after pressure. The advanced structure makes the sealing performance of the trunnion ball valve stable, labor-saving and long service life, which is very suitable for long-distance pipelines and general pipelines.

Design Features

The ball valve are designed in accordance with ISO14313、API 6D、BS 5351、GB/T 19672;

Simple structure with good sealing performance and small torque;

Full bore and reduced bore design with the minimum flow resistance (zero actually);

Emergency sealant injection;

Cavity pressure self relief;

Independent ball and stem;

Low emission packing;

Fire safe, anti-static and anti-blowout stem design;

Valve seat function DBB, DIB-1, DIB-2;

Optional extended bonnet.

Product Range

Body material: carbon steel
Nominal diameter:2”～60”（DN50~DN1500）

End Connection: RF, RTJ, BW

Pressure range: Class150～2500（PN16~PN420）

Working temperature:-46℃～+200℃

Operation: Wrench, worm gear, electric, pneumatic, gas over oil actuator and electro-hydraulic actuator

 Note:

1) Forged valve body is compact in structure, not easy to be defective, its structure size is not limited by dies, and its pressure-bearing performance is reliable. It is mostly used in the manufacture of high pressure, oxygen condition, small caliber or other small batch valves, and forgings are usually selected under high temperature, high pressure or low temperature or special medium. Castings are generally only suitable for medium and low pressure, and are mostly used in standardized batches of formed valves. In production.

2) The material A351 CF3M is different from A182 F316L: the material corresponding to the two standards is 316 stainless steel. CF3M means casting and is often used as valve material. The corresponding forged steel code is A182 F316L. ASTM A216 WCB is a casting, its forging is A105; SS304 is A351-CF8, and the forging is A182-F304.